when we first heard about the nsa surveillance going on, we heard about program called prism. now, how is prism different than the x key score. >> that's right. okay. prism is when the nsa targets orders to specific silicon valley companies to get information on specific foreign terror suspects. x key core is much wider in scope. one description that it's like vacuuming a who will room on americans. sharon, thank you for that. >>> new revelations tonight in the case of the three women held hostage for years in the cleveland house. documents show how arielle castro lured them to his basement in the first place. amanda barry, gina dejesus and michelle knight kept diaries. instead they were chained up and raped repeatedly over the years. if he wanteded to punish them, he kept them in the cold basement or the sweltering attic. they got one meal a day and one shower a week. last friday, castro pled guilty to rape, kidnapping and aggravated murder. he'll spend the rest of his life in prison. >>> starting tomorrow, two more states will ring wedding bells for gay and lesbian couples.